This invention relates to preparing stable suspensions of particulate materials.
Suspending mediums are commonly used for oil field additives, lubricants, coatings and paints. The industry goal has been, and still is, to improve the stability of these suspending mediums to extend the shelf life of products which contain suspended particulate materials. Settling out of the suspended particulate materials is a pronounced problem with materials which have high specific gravities such as tin or zinc particles. Those suspensions which do resist settling tend to be too viscous to pour.
Attempts to meet the above stated goals have been made in the art. Such efforts have employed a wide variety of agents including mixtures of organophyllic clays and water or oils, and polyethylene and mineral oil. Although these suspending mediums or compositions individually and collectively have improved on the art, the ultimate goal of providing an ideal suspension, i.e. one which resist settling, is pourable, easy to manufacture and is useable over a wide temperature range, remains to be solved.